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N18 ICD-10-CM Code: Chronic kidney disease (CKD)

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

Tabular directives
11 Excludes2 · 3 use-additional codes · 3 code-first instructions

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for N18 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on N18 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from N17-N19

Code First

Underlying conditions that must be sequenced before this code.

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code, if applicable, to identify:
  • associated cachexia (E88.A)
  • kidney transplant status (Z94.0)

Coder workflow for N18

MedCoder structured workflow — derived from this code’s own official record

Before you code N18

  1. N18 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewN18.1, N18.2, N18.3, N18.4, N18.5, N18.6, N18.9

    See the relationships section · Guide: How to choose an ICD-10-CM code →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath N18?
    Yes → Select that code and continue the checks below on its own page.
    No → N18 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewN18.1, N18.2, N18.3, N18.4, N18.5, N18.6, N18.9

  2. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then N18.
    No → Continue; do not add an underlying condition the record does not document.

    ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

Consider N18. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Acuity
Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes2 — not part of N18(11 notes)

    Coding workflow: The conditions named in this note are not included in N18. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareP96.0, N14, R39.2, D59.3, K76.7, O90.41

    See the official tabular notes · Guidelines I.A.12.b

  • Code First — sequencing check(3 notes)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before N18. Do not add an underlying condition the record does not document.

    ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

    See the official tabular notes · Guidelines I.A.13

  • Use Additional Code — after identifying N18(3 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with N18 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewE88.A, Z94.0

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The underlying condition the Code First note names is documented alongside this condition.

Coding question: How are the two sequenced?

Path: Review the Code First note.

Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).

ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with N18?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewE88.A, Z94.0

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Chronic kidney disease (CKD) is a non-billable ICD-10-CM category code (N18). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

2) Hypertensive Chronic Kidney Disease Assign codes from category I12, Hypertensive chronic kidney disease, when both hypertension and a condition classifiable to category N18, Chronic kidney disease (CKD), are present. CKD should not be coded as hypertensive if the provider indicates the CKD is not related to the hypertension.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

The appropriate code from category N18 should be used as a secondary code with a code from category I12 to identify the stage of chronic kidney disease.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

The ap propriate code from category N18, Chronic kidney disease, should be used as a secondary code with a code from category I13 to identify the stage of chronic kidney disease.

Chapter 14: Diseases of Genitourinary System (N00-N99)

2) Chronic kidney disease and kidney transplant status Patients who have undergone kidney transplant may still have some form of chronic kidney disease (CKD) because the kidney transplant may not fully restore kidney function. Therefore, the presence of CKD alone does not constitute a transplant complication. Assign the appropriate N18 code for the patient’s stage of CKD and code Z94.0, Kidney transplant status. If a transplant complication such as failure or rejection or other transplant complication is documented, see section I.C.19.g for information on coding complications of a kidney transplant. If the documentation is unclear as to whether the patient has a complication of the transplant, query the provider.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Sequencing: 3 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
  2. 3 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 11 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name N18 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: N19 — Unspecified kidney failure.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Code First instructions across 2 chapters: D63.1 — Anemia in chronic kidney disease, I5A — Non-ischemic myocardial injury (non-traumatic).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Use Additional Code instruction: I75.81 — Atheroembolism of kidney.

These codes instruct coders to additionally report this code when it applies.

Referenced by 12 Code Also instructions across 3 chapters: D59.3 — Hemolytic-uremic syndrome, E20.810 — Autosomal dominant hypocalcemia, N00 — Acute nephritic syndrome, N00-N08 — Glomerular diseases (N00-N08), N01 — Rapidly progressive nephritic syndrome, N02 — Recurrent and persistent hematuria, N03 — Chronic nephritic syndrome, N04 — Nephrotic syndrome, N05 — Unspecified nephritic syndrome, N06 — Isolated proteinuria with specified morphological lesion, N07 — Hereditary nephropathy, not elsewhere classified, N08 — Glomerular disorders in diseases classified elsewhere.

These codes suggest coding this condition alongside when both are present.

Contextual Map

Every relationship of N18 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run N18 with these 24 related codes in Claim Check

Hierarchy

Excludes2 (15)

Code First

Use Additional Code

Referenced by Excludes1 notes

Referenced by Code First instructions

Referenced by Use Additional Code instructions

  • I75.81 — Atheroembolism of kidney[Use Additional Code]: “code for any associated acute kidney failure and chronic kidney disease (N17.-, N18.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions (12)

Nearest codes (10)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Can N18 be billed directly?

No. N18 (Chronic kidney disease (CKD)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "N18 — Chronic kidney disease (CKD)." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/n18-chronic-kidney-disease-ckd

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Chronic kidney disease (CKD)

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to N18 in its code family, with their registry titles.